docs: def make_tb2rad_lut(self, filepath, normalized=True):
          """Generate a Tb to radiance look-up table"""
          tb_ = np.arange(TB_MIN, TB_MAX, self.tb_resolution)
          retv = self.tb2radiance(tb_, normalized=normalized)
          rad = retv['radiance']
          np.savez(filepath, tb=tb_, radiance=rad)